My guess is because of people who likes to enable all the stuff and then complain that a game runs like shit.
I would like to say you are wrong but......
I see that way too often on various boards, even enthusiast ones like Overclock.net or Guru3d. People who genuinely don't get that no high-end features comes for free.
Regarding ROTTR the marketing on the PC version is subtle to say the least. I would not mind some footage with some basic rundown of the various improvements they have made.
Too much to ask I know. Oh, and for those wondering the
trailer on the Steam page is no PC footage, it's just xbone trailer with the release date changed. No wonder it looked identical.
I'm disappointed that Nvidia have not been allowed (this is what I'm assuming) to say much about it either.